Desired outcomes for arthroscopic ligament reconstruction surgery are generally achieved by establishing the proper shape and placement of torn tissue. While performing such surgery, a surgeon typically makes a small incision in a patient's skin covering the surgical site (e.g., a bone joint) to allow a surgical instrument to be placed in the bone joint and manipulated through arthroscopic visualization. One such instrument, sometimes known as a retro guidewire reamer, can be configured to operate in both an antegrade drilling mode and a retrograde cutting mode. The reamer is used to create tunnels through the patient's bone which are subsequently filled with a tissue graft, replicating the original damaged tissue.
For a torn anterior cruciate ligament (ACL) reconstruction, for example, one approach to achieving proper placement of the tissue graft includes creating a tunnel from the outside to the inside (i.e., from the “outside in”) of the patient's femur. With this approach, a surgeon places a guidewire through bone along an established path for creation of the bone tunnel. The surgeon then determines the size of a primary bone tunnel as well as the size of a counterbore through the bone appropriate to fit the replacement tendon graft. Once the proper size of the bone tunnel is established, the surgeon places the reamer with an appropriately sized drill bit over the guidewire to create the primary bone tunnel in an antegrade manner. The surgeon then retracts the guidewire and activates a mechanism to open or deploy a cutting member of the retro guidewire reamer within the bone joint. The surgeon then uses the cutting member to create a counterbore through the bone in a retrograde manner. Once the counterbore is drilled, the surgeon activates the mechanism to close the cutting member, allowing the reamer to be withdrawn through the primary bone tunnel created by the drill bit.
In some instances, device failure can occur when the surgeon attempts to deploy the cutting member before the guidewire is fully retracted from the device. A similar error can occur when the surgeon attempts to rotate the cutting member back to its original position while the guidewire is still engaged with the cutting member. These errors can potentially cause damage to the mechanical joint which allows the cutting member to deploy and retract, rendering the device inoperable and requiring a replacement device.